Propeller retention means



1964 D. R. HART ETAL PROPELLER RETENTION MEANS Filed Feb. 9, 1962 7 NW v MIN -m Q\ t I b\ m\ mu 5 l\ 3 mu w\ N m A NN ififi QN k\ T w 3.

r m m? w T41 R H6 0 w M mwm United States Patent 3,144,909 PROPELLER RETENTION MEANS Dexter R. Hart, St. Paul, and Kurt 0. W. Moebius, M|nneapolis, Minn., assignors t0 McCulloch Corporatn,Los Angeles, Cali, a corporation of Wisconsin Filed Feb. 9, 1962, Ser. No. 172,278 2 Claims. (Cl. 170-177) This invention relates to means for axially retaining a marine motor propeller on a shaft on which it is mounted.

In conventional mounting of a marine propeller, such as on an outboard motor, on its carrying shaft, the propeller hub is secured to the shaft by a pin which is readily shearable when the propeller engages an obstruction freeing the shaft from driving connection with the hub. It has been common to cap the distal end of the propeller shaft with a removable nut or cap to prohibit axial displacement of the propeller when the pin breaks. In the interest of economy the nut may be made of a relatively soft material such as nylon.

It is found, however, that when the pin shears the front end of the still rotating nut may be chewed up or otherwise damaged by the idle propeller bearing thereagainst. It is accordingly desirable to prevent such dam-' age that a retainer be provided which is rotatable with the propeller on the shaft when the shear pin has broken. 1

An object of the invention is to provide a novel pro-.1 peller retention cap and means for attaching the cap to the propeller shaft of an outboard motor or the like which allows rotation of the cap on the shaft and ready removal of the cap where necessary.

Another and more specific object of the invention is; to provide a new and'impr'o'v'ed "retention means for holding a propeller on a shaft, which is rotatable on the shaft with the propeller when necessary and which means may be simply and quickly removed from the shaft with-, out disassembly when it is' desired to gain access to the propeller.

With these objectives in mind the invention broadly comprises a cap adapted to fit over the end portion of the propeller shaft having a shoulder formed therein, and a clip slidably mounted in the cap for manual movement in a radial direction between an inner operative position gripping the shaft adjacent said shoulder and an outer release position out of engagement with the shaft allowing removal of the cap, said clip having a control handle disposed outside of the cap and stop means inside of the cap limiting its outward movement.

The above mentioned and additional objects of the invention will be brought to light during the course of the following specification, reference being made to the accompanying drawing, in which- FIG. 1 is a plan view of the propeller of an outboard motor and the retention means forming the subject of this invention.

FIG. 2 is an axial section through the propeller hub and retainer cap taken along line 22 of FIG. 1 but showing the propeller shaft and retainer holding clip in elevation.

FIG. 3 is a vertical section taken through the cap along line 3-3 of FIG. 2.

FIG. 4 is like FIG. 3 but shows the clip in its shaft releasing position.

Referring now more particularly to the drawing, ICffili ice - A propeller 11 has its annular center hub portion 12 mounted on the shaft such as by a mounting sleeve 14 with an annular friction ring 15 of rubber or the like disposed between the sleeve 14 and the interior wall of hub portion 12. Ring 14 is conventionally bonded to either the sleeve or the propeller portion 12 and is held It will thus be understood that the propeller 11 and its hub components will rotate with shaft 10 as long as pin 16 is intact and in place. In the event that the propeller engages an unyielding obstruction. pin 16 will break allowing the shaft 10 to rotate freely within the propeller hub. As thus far described the construction is conventional.

To the rear of the propeller mounting sleeve 14, the

shaft 10 is provided with a peripherally encircling groove 17. This groove is rectangular in cross section with the rear wall 18 thereof disposed on a plane perpendicular to the shaft axis and forming a shoulder facing axially forward toward the propeller.

A retainer element 13, commonly referred to as a cap or nut, is provided to enclose the rear end portion of the shaft 10. This element has an annular wall 19, seen in cross section in FIG. 2, which tapers generally toward the rear closed end 20 thereof. The internal chamber in the retainer is enlarged as at 21 near its forward end for reception of the rear end of sleeve 14 and the shear pin 16. The chamber is then reduced in diameter for which extends diametrically through the walls 19 and across the internal chamber, the plane of the slot lying perpendicular to the center axis of the element. The slot is disposed rearwardly of chamber portion 21 and in radial alignment with the groove 17 on the shaft 10 when the element 13 is in position on the shaft with its,

front face 24 closely spaced behind the propeller hub portion 12. The slot 22 is slightly reduced in width near one end forming shoulders 25 (FIG. 3) the purpose of which will be shortly understood. It will also be noted from observance of FIG. 3 that slot 22 is substantially greater in width than the diameter of the shaft portion adjacent thereto, thus allowing a substantial amount of clearance at each side of the shaft.

A clip for securing the nut 13 against axial movement on the shaft 10 is denoted generally by the numeral 28. This clip has a general U-shape with the bight portion thereof bent over as at 29 to lie substantially perpendicular to the common plane of the clip legs 30. The clip is preferably formed of spring tempered wire with the legs 30 thereof extending away from the portion 29 in substantial parallelism, then arching slightly as at 31 on a radius substantially equal to that of the grooved portion of shaft 10, and terminating in outwardly hooked stop portions 32, making that end of the clip substantially wider than the reduced portion of the slot 22.

FIGS. 1, 2 and 3 show the retainer element 13 in normal position behind the propeller. Clip 28, held firmly in the slot 22, is in its inner position with the leg portions 31 thereof seated in opposing portion of the groove 17 to secure the retainer 13 on the shaft. A portion of the periphery of member 13 is flattened as at 23 to mate with the handle 29. In this condition both the propeller 11 and the retainer will rotate with the shaft 10.

reception of the remaining reduced end portion of shaft 10.

r The element 13 is provided with a wide flat slot 22' In the event that the shear pin 16 should break to free the shaft from its driving connection with the propeller, the propeller hub portion 12 will bear against the front edge 24 of the retainer 13. Inasmuch as the member 13 is drivingly engaged with the shaft 10 only through the frictional engagement of the clip 28 with the shaft, the rearward pressure of the propeller will overcome the clip friction and free the shaft 10 for rotation within the element 13. The propeller hub and retainer 13 will accordingly rotationally stay together irrespective of the movement of the shaft.

While the clip 28 will under excessive pressure rotate on the shaft it will firmly retain its seated position in the groove 17, thus locking the element 13 against axial movement on the shaft.

When it is desired to remove the retainer 13 to replace the shear pin or to change propellers, the handle portion 29 of the clip is grasped and pulled outwardly bringing the clip to its outer position such as shown in FIG. 4. The clip stop hooks 32 will engage the shoulders 25 to prohibit complete withdrawal of the clip. In this position the clip is completely removed from the groove 17 and thus clear of shoulder 18 allowing the element 13 to be pulled off of the end of the shaft. Should it for some reason be desirable to remove the clip 28 from the retainer, this can be done by squeezing the clip legs together until shoulders 25 are cleared by the hook portions 32.

When the propeller is again ready for operation the retainer 13 is replaced and clip 28 is pushed inwardly again to its locking position, as shown in FIG. 3.

The construction described accordingly economically and effectively carries out the aforementioned objectives. It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described our invention, what we claim to be new and desire to protect by Letters Patent is:

1. In a marine engine having a propeller shaft, a propeller hub mounted on said shaft, said shaft having a shoulder thereon facing the hub, a retainer for prohibiting axial movement of the propeller hub along the propeller shaft, which comprises an annular retention member encircling the shaft adjacent the shoulder, said retention member having a slot extending radially therethrough, said slot being reduced in width by a shoulder near the outer periphery of the retention member, a U- shaped retention clip held in said slot for radial sliding movement between a locking position with the legs of the clip engaging against said first mentioned shoulder and a radially outward shoulder releasing position allowing axial movement of the retention clip, and said clip legs having portions spaced apart greater than the width of said slot reduced portion prohibiting complete outward removal of the clip from the retention member.

2. In a marine engine having a propeller drive shaft, a propeller hub mounted on the shaft, a retainer element for securing the propeller hub against axial movement in one direction along the propeller drive shaft, said shaft having a peripheral groove spaced from said hub, said retainer element having a slot extending radially therethrough, said element having an annular wall encircling the grooved portion of the shaft, a retention clip mounted in said slot for sliding movement in a radial direction between inner and outer positions, said clip having a pair of spring tensioned legs spaced diametrically of the shaft and lying on the plane of said groove perpendicular to the shaft axis to seat in diametrically opposing portions of the groove and grip the shaft therebetween when the clip is in its inner position, the clip having a leg connecting portion disposed outside of the retainer element to serve as a handle for manually sliding the clip between said positions, projections on the clip legs engageable with said annular wall to limit outward sliding movement of the clip, and said clip legs and projections lying entirely outside of said shaft groove to release the retainer element from the shaft when the clip is in its outer position.

References Cited in the file of this patent UNITED STATES PATENTS 2,111,245 Irgens Mar. 15, 1938 2,512,690 Smith June 27, 1950 2,512,691 Smith June 27, 1950 2,564,605 Martin Aug. 14, 1951 2,760,258 Rieger Aug. 28, 1956 2,993,544 Carlson July 25, 1961 3,002,365 Liljequist Oct. 3, 1961 FOREIGN PATENTS 402,362 Germany Sept. 18, 1924 736,719 Great Britain Sept. 14, 1955 

1. IN A MARINE ENGINE HAVING A PROPELLER SHAFT, A PROPELLER HUB MOUNTED ON SAID SHAFT, SAID SHAFT HAVING A SHOULDER THEREON FACING THE HUB, A RETAINER FOR PROHIBITING AXIAL MOVEMENT OF THE PROPELLER HUB ALONG THE PROPELLER SHAFT, WHICH COMPRISES AN ANNULAR RETENTION MEMBER ENCIRCLING THE SHAFT ADJACENT THE SHOULDER, SAID RETENTION MEMBER HAVING A SLOT EXTENDING RADIALLY THERETHROUGH, SAID SLOT BEING REDUCED IN WIDTH BY A SHOULDER NEAR THE OUTER PERIPHERY OF THE RETENTION MEMBER, A USHAPED RETENTION CLIP HELD IN SAID SLOT FOR RADIAL SLIDING MOVEMENT BETWEEN A LOCKING POSITION WITH THE LEGS OF THE CLIP ENGAGING AGAINST SAID FIRST MENTIONED SHOULDER AND A RADIALLY OUTWARD SHOULDER RELEASING POSITION ALLOWING AXIAL MOVEMENT OF THE RETENTION CLIP, AND SAID CLIP LEGS HAVING PORTIONS SPACED APART GREATER THAN THE WIDTH OF SAID SLOT REDUCED PORTION PROHIBITING COMPLETE OUTWARD REMOVAL OF THE CLIP FROM THE RETENTION MEMBER. 